JP2023125687A - Gas-liquid separator - Google Patents

Abstract

To provide a gas-liquid separator which suppresses pressure loss of gas, and can efficiently separate water.SOLUTION: A gas-liquid separator 1 includes a housing 10 having an internal space 11, a cylindrical upper flow passage 20 which is arranged in the internal space 11 of the housing 10 and distributes water-containing gas supplied from outside of the housing 10, a gas-liquid separation part 40 which is arranged inside the upper flow channel 20 and separates water from the water-containing gas, a cylindrical lower flow channel 30 which is arranged in the internal space 11 of the housing 10 and distributes water-removal gas after the water has been separated by the gas-liquid separation part 40, and a water storage part 50 which is arranged in the housing 10 and stores the water separated by the gas-liquid separation part 40. In the gas-liquid separator 1, the upper flow passage 20 and the lower flow passage 30 are arranged so that a shaft core X of the upper flow passage 20 and a shaft core Y of the lower flow passage 30 are coaxial with each other when viewed in a vertical direction.SELECTED DRAWING: Figure 2

Description

The present invention relates to a gas-liquid separator.

A fuel cell achieves power generation by supplying hydrogen gas to the anode side and supplying air containing oxygen to the cathode side. The anode off-gas discharged from the anode side of the fuel cell during power generation contains unreacted hydrogen and water, and the cathode off-gas discharged from the cathode side contains air and water. In a fuel cell, in order to reuse unreacted hydrogen, a gas-liquid separator that removes water contained in the anode off-gas is provided in a flow path that returns the anode off-gas to the anode side. Further, the cathode off gas is supplied to a humidifier and water is separated therefrom, and some systems are equipped with a gas-liquid separator in the flow path between the fuel cell and the humidifier to preliminarily separate water.

Patent Document 1 discloses a cylindrical main body whose upper and lower sides are sealed, an inlet pipe provided near the cylindrical upper part of the main body and in the tangential direction, and a central part of the top plate of the main body. A gas-liquid separator for a fuel cell vehicle is disclosed, which includes an outlet pipe provided to protrude inside and outside of the main body, and a drain pipe provided at the lower part of the main body.

In this gas-liquid separator for fuel cell vehicles, a gas-liquid mixed gas introduced from an inlet pipe is separated into gas and liquid by centrifugal force. The separated water is sent below the main body by a spiral moisture guiding means formed on the inner circumference of the main body, and is discharged from the drain pipe. The gas from which the water has been separated is exhausted from the outlet pipe.

Japanese Patent Application Publication No. 2003-311185

The gas-liquid separator for fuel cell vehicles described in Patent Document 1 introduces a gas-liquid mixed gas from the horizontal direction into the main body, separates water by centrifugal force, and separates the water from the vertical direction. Since the structure is to exhaust gas, it is necessary to bend the direction in which the gas flows within the main body by 90 degrees, which increases pressure loss.

Therefore, there is a need for a gas-liquid separator that can suppress gas pressure loss and efficiently separate water.

The gas-liquid separator according to the present invention includes a housing having an internal space, and a cylindrical upper channel disposed in the internal space of the housing through which water-containing gas supplied from the outside of the housing flows. , a gas-liquid separator disposed inside the upper flow path to separate water from the water-containing gas; and a water removal unit disposed in the internal space of the housing after water is separated in the gas-liquid separator. The upper flow path includes a cylindrical lower flow path through which gas flows, and a water storage section that is disposed in the housing and stores water separated by the gas-liquid separation section. The upper flow passage and the lower flow passage are arranged such that the axis of the passage and the axis of the lower flow passage are coaxial.

According to this characteristic configuration, the water contained in the water-containing gas linearly supplied to the upper flow path is separated in the gas-liquid separation section. Thereafter, the water-removal gas after the water has been separated flows vertically downward through the lower flow path coaxial with the axis of the upper flow path. Thereby, it is possible to realize a gas-liquid separator that can efficiently separate water while suppressing pressure loss due to the gas-liquid separation section.

As another characteristic configuration, the gas-liquid separator further includes an annular blocking wall disposed on the outer circumferential surface of the lower flow path in a posture inclined with respect to the extending direction of the lower flow path, and the A through hole is provided at the boundary between the outer circumferential surface of the lower flow path and the inner circumferential surface of the blocking wall.

According to this characteristic configuration, even if some of the water separated from the water-containing gas adheres to the upper surface of the blocking wall, the water can flow from the through hole along the outer circumferential surface of the lower flow path, so that the blocking wall No water collects on the top. Thereby, water adhering to the upper surface of the blocking wall can be prevented from flowing into the lower channel.

As another characteristic configuration, in the gas-liquid separator, a lower end in the vertical direction of the upper flow path and an upper end in the vertical direction of the lower flow path are separated from each other, and the outer diameter of the lower end of the upper flow path is , is larger than the inner diameter of the inner circumferential surface of the lower flow path.

According to this characteristic configuration, it is possible to prevent water dripping from the lower end of the upper channel in the vertical direction from entering the lower channel.

As another characteristic configuration, in the gas-liquid separator, the gas-liquid separation section includes a plurality of separation blades arranged on the inner circumferential surface of the upper flow path in an inclined attitude with respect to the flow direction of the water-containing gas. When viewed along the vertical direction, each of the separation blades is arranged so as to partially overlap with the adjacent separation blade.

According to this characteristic configuration, the flow direction of the water-containing gas can be changed from a linear flow in the vertical direction to a swirling flow, making it possible to separate water by centrifugal force. Furthermore, it is possible to prevent the water-containing gas supplied to the upper flow path from passing through the gas-liquid separation section without colliding with the separation blades.

Another feature of the gas-liquid separator is that the housing has an inclined surface that collects water separated in the gas-liquid separation section into the water storage section.

According to this characteristic configuration, the water separated in the gas-liquid separation section can be reliably collected in the water storage section.

FIG. 1 is a perspective view of a gas-liquid separator according to the present embodiment. FIG. 2 is a longitudinal cross-sectional view of a gas-liquid separator. It is a top view of a gas-liquid separator. FIG. 3 is a plan view of the lower housing.

Hereinafter, a gas-liquid separator according to an embodiment of the present invention will be described based on the drawings. However, the present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist thereof.
〔overall structure〕
1 and 2 show a gas-liquid separator 1 that separates water contained in cathode off-gas (an example of water-containing gas) discharged from the cathode side of a fuel cell (not shown) mounted on a fuel cell vehicle (FCV). It is shown. The gas-liquid separator 1 includes an upper flow path 20, a lower flow path 30, a gas-liquid separation section 40, and a water storage section 50 in the internal space 11 of the housing 10. The housing 10 is constructed by fastening an upper housing 12 and a lower housing 13 with a plurality of bolts 14. An inlet 15 connected to the upper flow path 20 is formed on the upper surface of the upper housing 12, and an exhaust port 16 connected to the lower flow path 30 is formed on the lower surface of the lower housing 13. An electromagnetic on-off valve 52 that controls the discharge of water stored in the water storage section 50 is provided on the outside of the lower housing 13 .

The gas-liquid separator 1 functions to separate and recover water contained in the cathode off-gas, and exhausts the cathode off-gas from which water has been separated (an example of water-removed gas) from the exhaust port 16. It is provided in the return flow path that returns to the humidifier (not shown) of the fuel cell. The cathode off gas from which water has been separated in the gas-liquid separator 1 is supplied to the humidifier and humidifies the oxidant gas (air containing oxygen) flowing through the humidifier. It is not necessary to separate all of the water contained in the The cathode off-gas from which water has been separated in the gas-liquid separator 1 still contains enough water to humidify the oxidant gas in the humidifier.

The fuel cell supplies fuel gas containing hydrogen gas to the anode side through an anode gas flow path (not shown), and supplies oxidizing gas to the cathode side through a cathode gas flow path (not shown). Power is generated by humidifying and supplying water. The reason for humidifying the oxidant gas supplied to the cathode gas flow path is to moisten the cathode side of the fuel cell and combine it with hydrogen, and the cathode off gas discharged from the cathode side contains unreacted oxidant gas. Contains water.

As shown in FIGS. 1 and 2, the gas-liquid separator 1 is configured such that cathode off-gas discharged from the cathode side of the fuel cell is passed through an upper flow path arranged in an internal space 11 of the housing 10 from an inlet 15 of the housing 10. 20 and flows through the upper channel 20, and water is separated from the cathode off gas in the gas-liquid separation section 40. The cathode off-gas from which water has been separated flows through the lower flow path 30 and is exhausted from the exhaust port 16. In addition, the water separated by the gas-liquid separation section 40 flows along the flow guide surface (an example of an inclined surface) 18 of the flow wall section 17 formed in the internal space 11 of the housing 10 to the water collection port 51 (see FIG. 4). The water flows down a water collection channel (not shown) from the water collection port 51 and is stored in the water storage section 50. The water stored in the water storage section 50 is discharged from the drainage channel 53 when the electromagnetic on-off valve 52 is opened.

〔housing〕
The gas-liquid separator 1 is installed in a vehicle with the vertical direction set as shown in FIGS. 1 and 2. The housing 10 has an upper housing 12 and a lower housing 13, and an internal space 11 is formed by fastening an upper flange 12a of the upper housing 12 and a lower flange 13a of the lower housing 13 with a plurality of bolts 14. .

The upper housing 12 and the lower housing 13 are made of resin, and a sealing material 13b is sandwiched between the upper flange 12a and the lower flange 13a. Note that the upper housing 12 and the lower housing 13 may be formed of metal such as aluminum.

An introduction port 15 that is circular in plan view (when viewed along the vertical direction) is formed as a through hole in the upper surface of the upper housing 12 (see FIG. 3). As shown in FIG. 2, the inlet 15 of the upper housing 12 has a cylindrical upper channel 20 extending vertically downward toward the inside of the upper housing 12 (the space constituting the internal space 11). They are attached across 20a. Cathode off-gas discharged from the cathode side of the fuel cell is supplied to the gas-liquid separator 1 from the inlet 15, and flows inside the upper channel 20 along the direction of gravity (vertically downward). Although the upper housing 12 and the upper flow path 20 are separate members in this embodiment, they may be formed integrally. Details of the upper channel 20 will be described later.

In the lower housing 13, a downstream wall portion 17, a lower flow path 30, a water storage portion 50, and a drainage flow path 53 are integrally formed. The lower flow path 30 has a cylindrical shape and extends vertically downward from the inside of the lower housing 13 (the space constituting the internal space 11) to the end. The cathode off-gas is supplied from the upper passage 20, flows inside the lower passage 30 along the direction of gravity, and is exhausted from the exhaust port 16 to the outside of the lower housing 13 (outside the gas-liquid separator 1).

The lower housing 13 is formed with a downstream wall 17 having an inclined position, the lower the position of which is closer to the water collection port 51 located above the water storage section 50, and a downstream guide surface on the inner surface of the downstream wall 17. 18 are formed. A portion of the lower flow path 30 projects further downward than the downstream wall portion 17 in the vertical direction. The lower end of the lower flow path 30 is a circular exhaust port 16 in plan view. In this embodiment, the lower flow path 30 is integrally formed as a part of the lower housing 13, but the lower flow path 30 may be formed as a separate member from other parts of the lower housing 13.

In the lower housing 13, a water collection port 51 is provided at the lowest position of the downstream guide surface 18, and the water collection port 51 and the water storage section 50 arranged below the water collection port 51 are arranged adjacent to the lower flow path 30. (See Figures 1 and 4). The water storage section 50 is a place where water separated from the cathode off gas is stored. The bottom of the water storage section 50 communicates with a drainage channel 53 via an orifice channel (not shown). The orifice flow path and the drainage flow path 53 are cut off when the electromagnetic on-off valve 52 is closed, and the water stored in the water storage section 50 is not discharged. When the electromagnetic on-off valve 52 opens, the orifice passage and the drainage passage 53 communicate with each other, and the water stored in the water storage section 50 flows through the orifice passage and is discharged from the drainage passage 53.

[Structure inside the housing]
As shown in FIG. 3, the housing 10 has a rectangular shape with rounded corners when viewed from above. The radius of the rounded corner differs depending on the corner, and the radius of the upper left corner is the smallest. The introduction port 15 is formed near the upper left corner. As described above, the upper channel 20 has a cylindrical shape that is connected from the inlet 15 and extends vertically downward. As shown in FIGS. 2 and 3, the axis X of the upper flow path 20 and the axis Y of the lower flow path 30 are arranged to be coaxial, and the inner diameter of the upper flow path 20 is the same as that of the lower flow path. The inner diameter of the channel 30 is larger than the inner diameter of the channel 30. Further, on the lower side in the vertical direction of the upper channel 20, an enlarged diameter portion 21 is formed, the outer diameter of which increases (widens outward) as it goes downward in the vertical direction. The enlarged diameter portion 21 has a linear flow path extending in the vertical direction that is curved outward and then has a diameter enlarged with a linear tapered surface.

A gas-liquid separation section 40 is disposed inside the upper channel 20 in the vertical direction. As shown in FIGS. 1 and 2, the gas-liquid separation unit 40 is provided on the inner circumferential surface 22 of the upper flow path 20 in an inclined position (approximately 50 degrees) with respect to the vertical direction, which is the direction in which the cathode off gas flows, and in the circumferential direction. It is configured with a plurality of (six in this embodiment) separation blades 41 arranged along the line. Further, as shown in FIGS. 2 and 3, each separation blade 41 is arranged so as to partially overlap with the separation blade 41 adjacent in the circumferential direction in plan view. This prevents the cathode off-gas supplied to the upper channel 20 from passing through the gas-liquid separation section 40 without colliding with the separation blades 41. Note that the number of separation blades 41 is not limited to six, and may be five or less or seven or more. Furthermore, the angle of the tilted posture is not limited to 50 degrees. These can be appropriately set depending on the content of water contained in the cathode off-gas and the amount of water that is desired to be included in the cathode off-gas after passing through the gas-liquid separation section 40.

In the gas-liquid separation section 40 , the cathode off-gas supplied vertically downward to the upper channel 20 collides with the separation blade 41 . As a result, the direction of flow of the cathode off-gas is changed from a straight vertical flow to a swirling flow. This allows separation of water by centrifugal force. Further, as the cathode offgas collides with the separation blade 41, water contained in the cathode offgas is separated. The separated water adheres to the separation blade 41. The separated water then flows from the separating blade 41 to the inner circumferential surface 22 of the upper channel 20 and the inner circumferential surface 22 of the enlarged diameter portion 21 and drips onto the downstream guide surface 18 . The cathode off-gas from which water has been separated by the separation vanes 41 and turned into a swirling flow passes through the gas-liquid separator 40, and then flows downward as a swirling flow while further separating water by centrifugal force. The water separated by centrifugal force travels along the inner circumferential surface 22 of the upper channel 20 and the inner circumferential surface 22 of the enlarged diameter section 21, and flows from the lower end 21a of the enlarged diameter section 21 to the downstream guide surface 18 of the downstream wall section 17. Drip. The water dripping onto the downstream guide surface 18 is guided by the inclined downstream guide surface 18 and collects at the water collection port 51, and from there flows through a water collection channel (not shown) and is collected in the water storage section 50 (FIG. 2, (See Figure 4).

As shown in FIG. 2, the upper end 30a of the lower flow path 30 in the vertical direction and the lower end 21a of the enlarged diameter portion 21 of the upper flow path 20 are slightly separated from each other in the vertical direction. In addition, an annular blocking wall 31 is arranged near the vertically upper end 30a of the outer circumferential surface 32 of the lower channel 30 in an attitude inclined (approximately 50 degrees) with respect to the extending direction of the lower channel 30. ing. The outer circumferential surface 31c of the blocking wall 31 is located slightly lower than the upper end 30a of the lower channel 30 in the vertical direction. The outer diameter of the lower end 21 a of the enlarged diameter portion 21 of the upper channel 20 is larger than the inner diameter of the inner peripheral surface 34 of the lower channel 30 . Therefore, water dripping from the lower end 21a of the enlarged diameter portion 21 does not enter the lower flow path 30, but adheres to the flow guide surface 18.

The blocking wall 31 is arranged to prevent the water dropped on the flow guide surface 18 from being rolled up by the flow (swirling flow) of the cathode gas after the water is separated and flowing into the lower flow path 30. Moreover, thereby, even when the fuel cell vehicle runs on a slope and the gas-liquid separator 1 is tilted, it is possible to suppress water on the flow guide surface 18 from flowing into the lower flow path 30. In this embodiment, the blocking wall 31 and the lower channel 30 are separate members, and the inner circumferential surface 31a of the blocking wall 31 and the outer circumferential surface 32 of the lower channel 30 are in close contact with each other.

As shown in FIG. 2, the inner peripheral surface 31a of the blocking wall 31 is located at the lowest position of the blocking wall 31 in the vertical direction. Therefore, when water adheres to the upper surface 31b of the blocking wall 31, the water flows toward the inner circumferential surface 31a, but the inner circumferential surface 31a and the outer circumferential surface 32 of the lower flow path 30 are in close contact with each other. Water does not leak from the boundaries of the area. However, if water is left to accumulate here, water may enter the lower flow path 30 due to vibration or other causes. Therefore, a plurality (four in this embodiment) of through holes 33 are formed at the boundary between the blocking wall 31 and the outer circumferential surface 32 of the lower flow path 30 (see FIG. 4). As a result, even when some of the water rolled up from the downstream guide surface 18 or part of the water separated in the upper channel 20 adheres to the upper surface 31b of the blocking wall 31, the water is not stored and the water is removed from the through hole 33. Water can flow along the outer circumferential surface 32 of the lower flow path 30, and water will not accumulate on the upper surface 31b of the blocking wall 31.

In this embodiment, the through hole 33 is formed in the blocking wall 31, but the present invention is not limited to this. The through hole 33 may be formed not in the blocking wall 31, or in addition to the blocking wall 31, in the outer circumferential surface 32 of the lower channel 30, or may be formed extending from the blocking wall 31 to the outer circumferential surface 32. . However, the through hole 33 formed in the outer peripheral surface 32 of the lower flow path 30 does not penetrate to the inner peripheral surface 34 of the lower flow path 30 . Note that in this embodiment, the lower flow path 30 and the blocking wall 31 are separate members, but they may be formed integrally.

On the other hand, the cathode off gas supplied from the upper flow path 20 to the lower flow path 30 circulates in the lower flow path 30 and is exhausted from the exhaust port 16 .

With such a configuration, the cathode off-gas linearly supplied to the upper flow path 20 collides with the separation blades 41 and is converted into a swirling flow, and at the same time, the water contained therein is separated. Thereafter, the cathode off-gas from which water has been separated flows vertically downward through the lower flow path 30 coaxial with the axis X of the upper flow path 20 while swirling, thereby suppressing pressure loss due to the gas-liquid separation section 40. , it is possible to realize a gas-liquid separator 1 that can efficiently separate water. In addition, by arranging the blocking wall 31 in the lower flow path 30, it is possible to prevent water that has dropped onto the flow guide surface 18 from being rolled up or when the fuel cell vehicle runs on a slope and the gas-liquid separator 1 is tilted. However, it is possible to prevent the separated water from flowing into the lower flow path 30. Even if some of the separated water adheres to the upper surface 31b of the blocking wall 31, a plurality of through holes 33 are formed at the boundary between the blocking wall 31 and the outer circumferential surface 32 of the lower channel 30. Therefore, water is not stored on the upper surface 31b of the blocking wall 31, and water can flow from the through hole 33 along the outer circumferential surface 32 of the lower channel 30.

[Another embodiment]
In addition to the embodiments described above, the present invention may be configured as follows (those having the same functions as the embodiments are given the same numbers and symbols as the embodiments).

(a) Although the gas-liquid separator 1 of the present embodiment separates water from cathode off-gas, it may also be used at a location where water is separated from anode off-gas.

(b) In the present embodiment, the expanded diameter portion 21 is expanded in diameter with a tapered surface that becomes straight after curving a straight flow path extending in the vertical direction outward. It's not something you can do. The expanded diameter portion 21 may be expanded in diameter by a tapered surface that bends a straight flow path outward and then becomes straight, or it can be expanded in diameter by a curved surface that curves a straight flow path outward. may be done.

The above configurations can be combined as much as possible.

INDUSTRIAL APPLICATION This invention can be utilized for a gas-liquid separator.

10: Housing 11: Internal space 18: Downstream guide surface (slanted surface)
20: Upper channel 21a: Lower end 22: Inner circumferential surface 30: Lower channel 30a: Upper end 31: Blocking wall 31a: Inner circumferential surface 32: Outer circumferential surface 33: Through hole 34: Inner circumferential surface 40: Gas-liquid separation section 41 : Separation vane 50 : Water storage part X : Shaft core Y : Shaft core

Claims (5)

a housing having an internal space;
a cylindrical upper channel disposed in the internal space of the housing, through which water-containing gas supplied from the outside of the housing flows;
a gas-liquid separation section that is disposed inside the upper flow path and separates water from the water-containing gas;
a cylindrical lower flow path disposed in the internal space of the housing, through which water removal gas flows after water is separated in the gas-liquid separation section;
a water storage part disposed in the housing and storing water separated by the gas-liquid separation part,
The upper flow path and the lower flow path are arranged such that the axis of the upper flow path and the axis of the lower flow path are coaxial when viewed in the vertical direction. liquid separator. further comprising an annular blocking wall arranged on an outer circumferential surface of the lower flow path in a posture inclined with respect to an extending direction of the lower flow path;
The gas-liquid separator according to claim 1, further comprising a through hole at a boundary between the outer circumferential surface of the lower flow path and the inner circumferential surface of the blocking wall. The lower end of the upper channel in the vertical direction and the upper end of the lower channel in the vertical direction are spaced apart,
The gas-liquid separator according to claim 2, wherein the outer diameter of the lower end of the upper flow path is larger than the inner diameter of the inner peripheral surface of the lower flow path. The gas-liquid separation unit is configured to include a plurality of separation blades arranged on an inner circumferential surface of the upper flow path in an inclined posture with respect to the flow direction of the water-containing gas,
The gas-liquid separator according to any one of claims 1 to 3, wherein each of the separation blades is arranged so as to partially overlap with the adjacent separation blade when viewed along the vertical direction. vessel. The gas-liquid separator according to any one of claims 1 to 4, wherein the housing has an inclined surface that collects the water separated in the gas-liquid separation section in the water storage section.

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